Surcharge to existing swimming pool 1

[shacked]

I am currently reviewing a set of proposed plan for new retaining walls and site landscaping located to an existing house on top of a slope.

Currently there is an existing pool that extends to the top of slope and the clients want to add new deck area at the top of slope. See attached pdf.

I am a little concerned since the grade will be raised behind the pool increasing loading to the pool foundation and I do not know how I should address this. I realize that the grade on the other side of the pool will be at the same height as the proposed deck, but would adding soil as shown in the attached pdf create an issue with the existing pool?

Should I try and find out who originally engineered the pool and contact them.

FYI this is located in southern California in an area known for poor soil conditions and landslides and I also do have a soils report. I spoke to the engineering geologist and he didn't seem too concerned with this.

Your thoughts?

 

[KootK]

...but would adding soil as shown in the attached pdf create an issue with the existing pool?

1) I agree that the extra fill would add load to the right side of the pool. That said, the left side of the pool would seem to already be experiencing the same load and I doubt that the pool was built asymmetrically.

2) If anything, I'd think that the added fill would make the pool less likely to slide downslope.

 

[JAE]

KootK - agree on your second point.
For your point 1 - the pool looks asymmetrical already so I wonder if there is a different wall design there?

 

[KootK]

For your point 1 - the pool looks asymmetrical already so I wonder if there is a different wall design there?

One does not know until they really know of course. That said, I struggle to imagine any one designing the ride side to be weaker than the left just because of the presence of what, I assume, is some kind of barrier or guard on that side.

The right side might also be designed for a full pool with no soil condition but, again, I'd be astonished if that led to an asymmetric design. If anyone wants to put money on this thing being asymmetric, I'm willing to give 8:1 odds.

 

[Tomfh]

Is it a normal concrete shell? If so it will be fine.

 

[shacked]

Thanks guys. I tend to think it will be ok,BUT since it is located at the top of a slope I have some reservations about it.

Just curious, how would you approach something like this? Request that the Architect provide the existing plans, or contact info of who designed the pool prior to submitting my proposal? I know this is a long shot, but this is a custom pool in a relatively new house, built in the 90's so there may be a decent chance that information exists.

 

[JAE]

By all means, if the plans/info is available take a look at it.
I was just observing that in your attachment the wall on the right was taller (and thicker maybe?) than the wall on the left.

Of course all we have here is a simple cross section at one point along the pool. The length of the pool, geometric shape (L shape, circular, etc.) all affect the pool's behavior.

And you have "good" pools designed by structural engineers where the reinforcement is correctly sized and positioned with appropriate wall thicknesses and base designs - VS - quickie shotcrete pools with #3 bars at 43" o.c. ea way against the dirt. Ha ha...just being hyperbolic a bit.